the effect of antiplatelet drugs on the patency rate of arterio-venous fistulae in hemodialysis patients

although arterialovenous fistulae (avf) is considered to be vital for chronic kidney disease (ckd) patients, but they may cause complications and problems. for instance they may fail soon after their creation. the most important cause of failure in these cases is intrafistula thrombus formation. whereas anti-platelet drugs are not routinely used after fistulae creation, we conducted this study to determine the effect of these drugs (aspirin and dipyridamol) on the patency of avfs. from sep 2003 to aug 2007, all ckd patients who needed avf for hemodilysis were included in our study. after fistulae creation, they were randomly divided in 3 groups. the first group was received aspirin and the second one with dipyridamol and the third one was the control group that received placebo. each group consisted of 130 patients. exclusion criteria were bleeding tendency, active peptic ulcer disease, pregnancy, lactation, use of anticoagulant and or non steroidal anti-inflammatory drugs, hepatic insufficiency and history of significant side effects from aspirin or dipyridamol. the patency of avf in the control, aspirin and dipyridamol groups were obtained 69.2%, 70.8% and 75.4% respectively. although the patency in the aspirin and the dipyridamol group were 1.6% and 6.2% more than the control group, but there was no statistically significant difference between them and placebo (the p-value was 0.892 for the aspirin group and 0.332 for the dipyridamol group). our study showed that neither the aspirin nor the dipyridamol can be effective on the patency of avf after 72 h even within six months period.